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> 1974 1.8L engine fast idle then stalls, Fuel injection issues
tshih914
post Feb 19 2023, 11:45 PM
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My 1.8L 914-4 with stock Bosch L?-Jetronic FI after being stored several years started to develop a hard to start problem. When finally started would stall when I give the gas pedal any input to raise the revs. I suspect there was some kind of intake air leak and while fiddling around had a backfire which blew the AF meter which I had Pelicanparts repaired. After replacing the fuel lines with the stainless ones from Tangerine Racing and flushing out the fuel system with Techron the engine started to run normally for a short time. Now the engine can be started and fast idles at 3000 rpm but again any input to rev up the engine results in stalling. The idle adjustment screw at the base of the throttle housing is fully closed. Any suggestions on how to fix?
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Van B
post Feb 20 2023, 04:24 PM
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Boy does that all sound familiar.

I’d still like to know what changed from when it ran normal.
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wonkipop
post Feb 20 2023, 04:39 PM
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QUOTE(Van B @ Feb 20 2023, 04:24 PM) *

Boy does that all sound familiar.

I’d still like to know what changed from when it ran normal.


it does sound a bit familiar, but not completely the same.

he said he left it to sit in storage for a few years.
something in there gave up the ghost during rip van winkle period.

they don't like sitting around.


EDIT - i seem to recall you ( @Van B ) got some weird thing where your 1.8 would run at 3000 rpm and not do anything else when you had something off. but its a couple of years ago and i can't find that thread anymore. maybe its my imagination and false memory? there was something i was asked to do by you and i think it was see if mine would start and run without the AFM plug in. mine would not. but yours would? and it was the way the fuel pump in yours had been wired in after moving to the front. mine is still stock and fuel pump is run off the AFM contacts after cranking phase. i could have this wrong. but yours would run and it ran at 3000 rpm? until you hit the throttle. my memory is not that good.

EDIT EDIT - can you see where i am going with this @Van B ?
we have to find your thread again and go through it.
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porschetub
post Feb 20 2023, 08:34 PM
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QUOTE(wonkipop @ Feb 21 2023, 11:39 AM) *

QUOTE(Van B @ Feb 20 2023, 04:24 PM) *

Boy does that all sound familiar.

I’d still like to know what changed from when it ran normal.


it does sound a bit familiar, but not completely the same.

he said he left it to sit in storage for a few years.
something in there gave up the ghost during rip van winkle period.

they don't like sitting around.

(IMG:style_emoticons/default/agree.gif) reckon the only thing that will cause that is a sticking air gate in the AFM,most normal air leaks will cause a high idle of say 1500 but generally not more but not 3000.
I had this with one of my old BMW's after top overhaul and found the AFM was full of crap,run great after a good clean,same system but the 914 AFM is known to suffer issues after backfire of I'am thinking that's happened.
Cheers.
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wonkipop
post Feb 21 2023, 02:57 AM
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QUOTE(porschetub @ Feb 20 2023, 08:34 PM) *

QUOTE(wonkipop @ Feb 21 2023, 11:39 AM) *

QUOTE(Van B @ Feb 20 2023, 04:24 PM) *

Boy does that all sound familiar.

I’d still like to know what changed from when it ran normal.


it does sound a bit familiar, but not completely the same.

he said he left it to sit in storage for a few years.
something in there gave up the ghost during rip van winkle period.

they don't like sitting around.

(IMG:style_emoticons/default/agree.gif) reckon the only thing that will cause that is a sticking air gate in the AFM,most normal air leaks will cause a high idle of say 1500 but generally not more but not 3000.
I had this with one of my old BMW's after top overhaul and found the AFM was full of crap,run great after a good clean,same system but the 914 AFM is known to suffer issues after backfire of I'am thinking that's happened.
Cheers.


yeah though this is even weirder and its something @Van B discovered.

it could be internal to the AFM like dirt, corrosion.wear on contacts etc.
but @tshih914 does have a new/rebuilt AFM now. i would think its probably pretty ok in those terms.

@Van B is on to this one i think.

if there was ever an argument for preserving a car in original condition - and by this i mean technically, not just aesthetically, it was during his relentless program to get his 1.8 running right. he knew i had a pretty unmolested car. so he kept giving me scenarios to try on mine. we didn't get the same outcomes. eventually between us all we cracked the fuel pump wiring trickery.

it sure is weird. but if that fuel pump is wired to the ignition circuit and it stays on, the car will run with the AFM disconnected from the ECU. but only with the TPS closed in idle position. no other position. and however it does it, it runs it at elevated revs.

and if its factory original wiring to fuel pump it won't run. it will fire, but it won't continue to run.
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Posts in this topic
tshih914   1974 1.8L engine fast idle then stalls   Feb 19 2023, 11:45 PM
Van B   Check to make sure your AFM is plugged in first.   Feb 20 2023, 01:28 AM
wonkipop   Check to make sure your AFM is plugged in first. ...   Feb 20 2023, 01:38 AM
Geezer914   1+ on the AFM not being connected. Check for vacu...   Feb 20 2023, 06:48 AM
tshih914   1+ on the AFM not being connected. Check for vac...   Feb 20 2023, 11:02 AM
wonkipop   1+ on the AFM not being connected. Check for va...   Feb 20 2023, 02:33 PM
Van B   [quote name='Geezer914' post='3059382' date='Feb ...   Feb 20 2023, 02:51 PM
wonkipop   1+ on the AFM not being connected. Check for va...   Feb 20 2023, 05:11 PM
dr914@autoatlanta.com   for the hell of it check the throttle body boot fo...   Feb 20 2023, 11:17 AM
r_towle   for the hell of it check the throttle body boot f...   Feb 28 2023, 08:57 PM
tshih914   for the hell of it check the throttle body boot ...   Feb 28 2023, 09:13 PM
rhodyguy   Would a vacuum leak down stream of AFM result in a...   Feb 20 2023, 01:22 PM
wonkipop   Would a vacuum leak down stream of AFM result in ...   Feb 20 2023, 02:17 PM
Van B   @wonkipop What alerts me is the no change in idle...   Feb 20 2023, 02:57 PM
wonkipop   [b]@[url=http://www.914world.com/bbs2/index.php?s...   Feb 20 2023, 03:20 PM
Van B   Yeah, I know, but I don’t care about California ...   Feb 20 2023, 03:33 PM
wonkipop   Yeah, I know, but I don’t care about California...   Feb 20 2023, 03:49 PM
jim_hoyland   All the above; L-Jet requires that there are no va...   Feb 20 2023, 03:52 PM
wonkipop   @Van B thinking about his problem there are two ...   Feb 20 2023, 04:13 PM
tshih914   @[url=http://www.914world.com/bbs2/index.php?show...   Feb 22 2023, 07:36 PM
Van B   Boy does that all sound familiar. I’d still lik...   Feb 20 2023, 04:24 PM
wonkipop   Boy does that all sound familiar. I’d still li...   Feb 20 2023, 04:39 PM
porschetub   Boy does that all sound familiar. I’d still l...   Feb 20 2023, 08:34 PM
wonkipop   [quote name='Van B' post='3059531' date='Feb 20 ...   Feb 21 2023, 02:57 AM
Van B   @wonkipop . What he described is exactly what hap...   Feb 20 2023, 06:45 PM
wonkipop   [b]@[url=http://www.914world.com/bbs2/index.php?s...   Feb 20 2023, 06:52 PM
wonkipop   @Van B which is to say as i suspected that high ...   Feb 20 2023, 06:56 PM
Geezer914   Go to Jeff Bowlsby's web site and get the Ljet...   Feb 20 2023, 07:13 PM
JeffBowlsby   You might also check the quality of the contacts i...   Feb 20 2023, 11:58 PM
wonkipop   You might also check the quality of the contacts ...   Feb 21 2023, 03:05 AM
Van B   Whatever you have back there by the batter near wh...   Feb 22 2023, 08:19 PM
tshih914   Whatever you have back there by the batter near w...   Feb 23 2023, 04:46 AM
Van B   Ok. Glad that thing wasn't some decel valve ri...   Feb 23 2023, 05:54 AM
Geezer914   Got rid of all that shit, the decel valve and the ...   Feb 23 2023, 08:45 AM
rjames   Got rid of all that shit, the decel valve and the...   Feb 23 2023, 11:50 AM
wonkipop   Got rid of all that shit, the decel valve and th...   Feb 23 2023, 11:54 AM
rhodyguy   Curious. What kind of condition are the oil fill t...   Feb 23 2023, 11:58 AM
wonkipop   ok @tshih914 [b]@[url=http://www.914world.com/...   Feb 23 2023, 12:00 PM
tshih914   ok [b]@[url=http://www.914world.com/bbs2/index.p...   Feb 23 2023, 07:58 PM
tshih914   ok [b]@[url=http://www.914world.com/bbs2/index....   Feb 23 2023, 08:16 PM
Van B   @wonkipop if the decel valve is full flow, it cou...   Feb 23 2023, 02:50 PM
wonkipop   [b]@[url=http://www.914world.com/bbs2/index.php?s...   Feb 23 2023, 03:58 PM
wonkipop   ok @Van B and [b]@[url=http://www.914world.com/...   Feb 23 2023, 06:50 PM
wonkipop   wow @tshih914 that was a quick test and reply. ...   Feb 23 2023, 09:01 PM
Van B   Definitely sounds like the AFM is doing stuff… b...   Feb 23 2023, 09:41 PM
tshih914   Definitely sounds like the AFM is doing stuff… ...   Feb 25 2023, 04:35 PM
tshih914   Definitely sounds like the AFM is doing stuff…...   Feb 25 2023, 04:36 PM
wonkipop   @tshih914 we are getting somewhere. this time it...   Feb 25 2023, 05:56 PM
Van B   @tshih914 The decel valve is on the other side. ...   Feb 25 2023, 06:45 PM
Van B   Yeah this is all wrong. You’ve got the wrong par...   Feb 25 2023, 06:49 PM
wonkipop   @Van B . i think he has got it right. he seems to...   Feb 25 2023, 07:22 PM
wonkipop   i think he has pulled this hose out and capped the...   Feb 25 2023, 07:26 PM
wonkipop   where i am going with my thinking @Van B is 1. ...   Feb 25 2023, 07:44 PM
Van B   Looks to me then like the decel valve is connected...   Feb 25 2023, 07:54 PM
wonkipop   @Van B . yes i noticed that kink in the small vac...   Feb 25 2023, 08:29 PM
wonkipop   i just watched your video @Van B . your decel is ...   Feb 25 2023, 08:56 PM
tshih914   I have every vacuum hose hooked up the same as the...   Feb 26 2023, 07:57 AM
wonkipop   I have every vacuum hose hooked up the same as th...   Feb 26 2023, 12:53 PM
Van B   I have every vacuum hose hooked up the same as th...   Feb 26 2023, 12:58 PM
wonkipop   I have every vacuum hose hooked up the same as t...   Feb 26 2023, 01:03 PM
r_towle   When I am hunting for a failure in the vacuum syst...   Feb 25 2023, 09:03 PM
Van B   74 L-Jetronic needs the distributor vacuum for any...   Feb 25 2023, 09:19 PM
wonkipop   74 L-Jetronic needs the distributor vacuum for an...   Feb 26 2023, 12:37 AM
nihil44   I've come in late here and haven't read al...   Feb 26 2023, 01:43 AM
wonkipop   I've come in late here and haven't read a...   Feb 26 2023, 01:54 AM
Geezer914   Last resort is to do a smoke test. Search on you ...   Feb 26 2023, 06:12 AM
Geezer914   I had a hell of a time finding a vacuum leak. It ...   Feb 26 2023, 09:39 AM
Van B   Ok so, I checked my AFM to see what I settled on f...   Feb 26 2023, 12:50 PM
wonkipop   ps in addition to blocking off snorkel the only ot...   Feb 26 2023, 12:58 PM
Van B   ps in addition to blocking off snorkel the only o...   Feb 26 2023, 01:00 PM
wonkipop   two suggestions by other members re injector seals...   Feb 26 2023, 01:58 PM
tshih914   two suggestions by other members re injector seal...   Feb 26 2023, 03:23 PM
wonkipop   two suggestions by other members re injector sea...   Feb 26 2023, 03:50 PM
wonkipop   direct link to AA vac hose kit. http://www.autoat...   Feb 26 2023, 03:58 PM
tshih914   direct link to AA vac hose kit. http://www.autoa...   Feb 26 2023, 05:18 PM
wonkipop   [quote name='wonkipop' post='3061145' date='Feb 2...   Feb 26 2023, 06:36 PM
nihil44   Here is the gasket on the AFM connector which wasn...   Feb 26 2023, 05:47 PM
nihil44   I have been pursuing running issues and vac leaks ...   Feb 26 2023, 06:28 PM
wonkipop   love your work @nihil44   Feb 26 2023, 06:39 PM
tshih914   love your work @[url=http://www.914world.com/bbs...   Feb 27 2023, 09:45 PM
wonkipop   love your work [b]@[url=http://www.914world.com...   Feb 28 2023, 02:26 AM
Van B   See the little hole near the front right off the A...   Feb 28 2023, 06:51 AM
tshih914   See the little hole near the front right off the ...   Feb 28 2023, 07:44 PM
wonkipop   See the little hole near the front right off the...   Feb 28 2023, 07:51 PM
tshih914   [quote name='tshih914' post='3061665' date='Feb 2...   Feb 28 2023, 08:47 PM
tshih914   [quote name='tshih914' post='3061665' date='Feb ...   Feb 28 2023, 09:10 PM
wonkipop   [quote name='tshih914' post='3061665' date='Feb ...   Feb 28 2023, 10:40 PM
Van B   Have you adjusted the decel valve or tested it to ...   Feb 28 2023, 08:07 PM
Van B   @wonkipop quit being so scared to that mean AFM. ...   Feb 28 2023, 08:09 PM
wonkipop   [b]@[url=http://www.914world.com/bbs2/index.php?s...   Feb 28 2023, 10:23 PM
Van B   Thats too low IMO. I posted the link to my thread ...   Feb 28 2023, 08:53 PM
Van B   Diaphragm is rubber. It gets hard and less flexibl...   Feb 28 2023, 09:58 PM
wonkipop   @tshih914 i knew i had this filed away but could...   Mar 2 2023, 09:55 PM
wonkipop   here is the rest of it. its an idiots guide. which...   Mar 2 2023, 10:15 PM
tshih914   here is the rest of it. its an idiots guide. whic...   Mar 3 2023, 10:11 PM
tshih914   [quote name='wonkipop' post='3062180' date='Mar 2...   Mar 3 2023, 10:12 PM
tshih914   [quote name='wonkipop' post='3062180' date='Mar ...   Mar 3 2023, 10:13 PM
tshih914   [quote name='tshih914' post='3062427' date='Mar 3...   Mar 3 2023, 10:18 PM
Van B   When you pinch the AAV hose, and the rpm drops to ...   Mar 3 2023, 10:42 PM
Van B   One other thing, I’m not understanding how you j...   Mar 3 2023, 10:43 PM
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